Various drinking vessels for providing a beverage mixed from a base liquid and a flavoring agent have been disclosed in the patent literature. See for example: U.S. Pat. No. 6,372,270 (Denny); U.S. Pat. No. 7,172,095 (Marshall); U.S. Pat. No. 7,299,936 (Singh et al.); U.S. Pat. No. 8,230,777 (Anson et al.); U.S. Pat. No. 8,657,158 (Snell); Published Application US2003/0072850 (Burniski); Published Application US2006/0021996 (Scott III, et al.); and Published Application US2014/0230659 (Waggonner et al.). Moreover various drinking vessels for providing a mixed beverage are commercially available. Examples of such commercially available vessels are those sold by Coolgear, Inc. under the trade designations Coolgear 20 oz. Aquaburst Bottle, Coolgear 20 oz. Ledge Double Wall Bottle, Coolgear 22 oz. Horizon Bottle, and Coolgear 56 oz. Infusion Bottle. Other such vessels are sold by CamelBak Products, LLC under the trade designations CamelBak Eddy. 75 L, CamelBak Eddy.Insulated, and CamelBak Groove 0.75 L. Still other commercially available vessels are the Thermos 18 oz. Hydration Bottle, the Nalgene MultiDrink bottle and the Brita Hard-Sided Bottle.
While such prior art drinking vessels are generally suitable for their intended purposes, they nevertheless leave much to be desired from one or more of various standpoints, e.g., ability to provide repeated desired concentrations of a mixed liquid or beverage, resistance to backflow into the base liquid, ease of use, simplicity of construction, Thus a need exists for a device for use with a drinking vessel or for a drinking vessel incorporating a device which overcomes the various disadvantages or needs of the prior art. The subject invention does that.